<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>SVG 编辑器</title>
    <style>
        #toolbox {
            position: absolute;
            top: 0;
            bottom: 0;
            left: 0;
            width: 250px;
            border-right: 1px solid #CCC;
        }

        #toolbox h2 {
            margin: 0;
            padding: 0;
            background: #EEE;
            font-size: 16px;
            height: 24px;
            line-height: 24px;
            padding: 5px 10px;
        }
        
        #toolbox form {
            padding: 10px;
        }

        #canvas {
            position: absolute;
            left: 260px;
            top: 10px;
            bottom: 10px;
            right: 10px;
            box-shadow: 2px 2px 10px rgba(0, 0, 0, .4);
            border-radius: 5px;
        }

        label {
            display: inline-block;
            width: 80px;
            text-align: right;
        }
    </style>
</head>
<body>
    <div id="toolbox">
        <h2>创建</h2>
        <form id="create-shape"></form>
        <h2>形状</h2>
        <form id="shape-attrs">
            请先创建图形
        </form>
        <h2>外观和变换</h2>
        <form id="look-and-transform" disabled="disabled">
            <p>
                <label style="display: inline;">填充</label>
                <input id="fill" type="color" value="#ffffff" />
            </p>
            <p>
                <label style="display: inline;">描边</label>
                <input id="stroke" type="color" value="#ff0000" />
                <input id="strokeWidth" type="range" value="1" />
            </p>
            <p>
                <label>translateX</label>
                <input id="translateX" type="range" min="-400" max="400" value="0" />
                
                <label>translateY</label>
                <input id="translateY" type="range" min="-400" max="400" value="0" />

                <label>rotate</label>
                <input id="rotate" type="range" min="-180" max="180" value="0" />

                <label>scale</label>
                <input id="scale" type="range" min="-1" max="2" step="0.01" value="1" />
            </p>
        </form>
    </div>
    <div id="canvas"></div>
</body>
<script>
    var SVG_NS = 'http://www.w3.org/2000/svg';

    // 图形及对应默认属性
    var shapeInfo = {
        rect: 'x:10,y:10,width:200,height:100,rx:0,ry:0',
        circle: 'cx:200,cy:200,r:50',
        ellipse: 'cx:200,cy:200,rx:80,ry:30',
        line: 'x1:10,y1:10,x2:100,y2:100'
    };

    // 默认公共属性
    var defaultAttrs = {
        fill: '#ffffff',
        stroke: '#ff0000'
    };

    var createForm = document.getElementById('create-shape');
    var attrForm = document.getElementById('shape-attrs');
    var lookForm = document.getElementById('look-and-transform');

    var svg = createSVG();

    function createSVG() {
        var svg = document.createElementNS(SVG_NS, 'svg');
        svg.setAttribute('width', '100%');
        svg.setAttribute('height', '100%');
        canvas.appendChild(svg);

        svg.addEventListener('click', function(e) {
            if (e.target.tagName.toLowerCase() in shapeInfo) {
                select(e.target);
            }
        });
        return svg;
    }

    function select(shape) {
        var attrs = shapeInfo[shape.tagName].split(',');
        var attr, name, value;

        // 更新 attrForm
        attrForm.innerHTML = "";
    }
</script>
</html>